I understand your papertrail descent includes a Thomas Couldham or Cowldham (1592–1675) born in Great Yarmouth.
You asked if there's a Coldham who has a YDNA result. Yes, i am one such. My Y67 result is posted at YSEARCH, but, i might not be the right 'line' of Coldham that you are seeking.
Do you have a YSEARCH Kit number; as i could easily do a TMRCA & GD between our data sets. (Did you test with www.ftdna.com?)
Given the 3 Coldham branches (see www.coldham.net) i have no idea if my branch is the one with this Thomas Cowldham in it. So far, I have no YDNA matches with any other COLDHAM's - probably because none of them has taken a YDNA test as yet...
FINALLY, I am very interested in a certain JOHN COULDHAM of Great Yarmouth who was apprenticed to a certain Edmund THAXTER, bailiff & merchant, in the 1660's. He was a close friend of Sir Thomas Browne of Cowdray, and travelled widely in Germany in Central Europe with Sir Thomas's son.
I'm working on YDNA matches with Moseley's (suggestive of Leicestershire/Brabazon links and possible with early Moselei's in Lorraine, France.)